The present invention relates to an automatic lubricating arrangement for the chisel of a hydraulic striking mechanism, the lubricating arrangement including a lubricant conveying unit connected to a lubricant reservoir for charging the chisel guide supporting the chisel with lubricant.
Hydraulic striking mechanisms (also called hydraulic hammers, or rock chisels, hydraulic chisels or rock breakers), are disclosed, for example, in German Offenlegungsschrift DE-OS 3,443,542 [corresponding to U.S. Pat. No. No. 4,646,854] and in many cases are fastened to a carrier unit having an associated energy supply, for example to the boom of a hydraulic excavator. When the striking mechanism is in use, its chisel, which is driven by means of a striking piston and performs a considerable number of longitudinal movements per second, is unavoidably stressed in the manner of a crowbar with the consequence that the chisel guides and the associated chisel section are subjected to great stress. In order to counteract excess wear and/or the possibility of friction welds in the region of the chisel guide, the latter must be lubricated sufficiently, if possible continuously or at regular time intervals which are adapted to the working conditions.
In the past, automatic lubricating devices of the above-mentioned type have supplied the chisel guide with liquid lubricants (that is oils or the like) and have been a part of a central supply unit equipped with relatively long lubricant conduits.
If the striking mechanism is subjected to high and possibly maximum stresses, the use of lubricants having a high solid lubricant content (for example chisel pastes) has been found to be particularly advantageous. Due to their viscosity and their content of solid lubricants, however, these substances are difficult to convey even at normal ambient temperatures, and thus under certain circumstances jeopardize the supply of lubricant into a region to be lubricated. For this reason, chisel guides have in the past been supplied with grease of the above-mentioned type by means of a grease filled, manually operated lever press. Since such a press is actuated manually, the lubricant supply depends solely on the expertise and/or attention of the respective operator.